Automatic underwater exploder



Feb. 18, 1969 D. P. EASTMAN 3,427,974

AUTOMATIC UNDERWATER EXPLODER Filed Jan. 25, 1960 DAVID P. EASTMAN BY zz-E2 AT TO United States Patent 3 Claims This invention relates to an automatic underwater exploder adapted to be employed in underwater missiles, and is more particularly directed to self-arming and impact sensitive exploders, wherein arming of the exploder is not accomplished until the missile has moved a predetermined distance from the launching site.

One of the objects of the invention is to provide an improved exploder mechanism and novel means to effect the arming of the exploder. The mechanism is simple and is adapted to arm the exploder at a predetermined distance from the missile launching site, the mechanism acting independently of time.

Another object of this invention is to provide an all mechanical time delay mechanism for arming the exploder which is responsive to ambient dynamic sea water pressure.

Another object of this invention is to provide an impact responsive firing device within the exploder, sensitive to a slight jarring of the exploder in armed position.

Briefly, in accordance with the invention there is provided an automatic underwater exploder for torpedoes adapted to be launched into water and to move therein. The exploder comprises a firing plunger, and means biasing the plunger into firing position. An impact sensitive means normally retains the plunger out of firing position and is responsive to impact for releasing the plunger means. Arming delay means are provided for precluding the release of the plunger means until the torpedo moves a predetermined distance away from the launching site. The arming delay means includes a water pressure responsive means movable within the exploder.

For a better understanding of the present invention, together with other and further objects thereof, reference is had to the following description taken in connection with the accompanying drawings, and its scope will be pointed out in the appended claims.

FIGURE 1 of the drawing illustrates an armed exploder in accordance with the invention, showing a longitudinal cross-section thereof taken generally along line 1-1 of FIGURE 2;

FIGURE 2 is a cross-sectional view taken on line 22 of FIGURE 1 showing the primer carrying member in armed position;

FIGURE 3 is a cross-sectional view taken on line 33 of FIGURE 1 modified to show the primer carrying member in unarmed position;

FIGURE 4 is a cross-sectional view taken on line 44 of FIGURE 1 showing portions of the locking mechanism retaining the primer carrying member in unarmed position; and

FIGURE 5 is a fragmentary perspective view to more clearly show the structure of the support member.

Referring now to the drawings there is provided a cylindrically shaped exploder casing 10, having within the forward end a closure cap 12, and having at its rearward end 11 an internal thread 14 to receive an explosive charge carrier 16. The carrier 16 may include an intermediate explosive charge 17 mounted in a casing 19 as well as a main explosive charge which is not shown.

Forward of the carrier 16 there is disposed an explosive primer carrying member 18, comprising a rectangularly formed body having an aperture 28 therein, containing a primer charge 20. The member 18 is adapted to slide transversely with respect to the casing to transpose the 3,427,974 Patented Feb. 18, 1969 charge filled aperture 28 from an unarmed position (FIG- URE 3) into a suitable arming position, shown in FIG- URES 1 and 2, as hereinafter further explained. More particularly, in armed position the aperture 28 is axially aligned with a firing plunger 40, intermediate charge 17 and the longitudinal central axis of casing 10; whereas in unarmed position the member 18 is off-set with respect to the latter, thereby removing aperture 28 from the firing line of plunger 40.

Initially the primer carrying member 18 is releasably locked in unarmed or olf-set condition, by means of latching ends 23 of locking arms 22 disposed in grooves 24 of member 18, as shown in FIGURE 3. The primer carrying member 18 is slidingly supported within a groove or cut-out 47 provided in a support member 35 permitting transverse movement. The movement to arming position is precluded by an arming delay mechanism 68, hereinafter further described.

The transverse movement of the primer carrying member 18 is effected when the locking arms 22 are retracted. The movement is caused by a pair of compression springs 26 each of which has one end disposed within an opening 27 in member 18, and has its opposite end extending outwardly and surrounded by a cylindrical shell 31, as shown in FIGURES 2 and 3. The springs 26 bias the member 18 toward the armed position shown in FIGURE 2, and react against the casing wall 10 of the exploder.

In armed condition latching ends 23 of arms 22 are disengaged from the grooves 24 in member 18, and an arm locking plate 33 is interposed between the latching ends 23 and the member 18, see FIGURE 4, to hold the latching ends 23 away from sliding member 1 8. The locking plate 33 is formed by a half circular segment which surrounds a circular end portion 36 of a weight support 35. The locking plate 33 is slidably held in place by a leaf spring 37 which exerts pressure against plate 33 biasing the plate toward the axial center of the device. The spring 37 is suitably attached to the support 35 by means of pins 38 inserted within the latter.

The firing plunger 40, located forward of primer carrying member 18, is surrounded by an impact sensitive means 54 which means normally retains the plunger 40 in its retracted position. The impact sensitive means 54 is in looking engagement with portions of the arming delay mechanism 68 to preclude the release of the plunger 40' to enable the missile to travel a pre-determined distance before arming.

To support the impact sensitive mechanism 54, the support 35 is provided with an outwardly flanged portion 42 which is integral with the portion thereof which surrounds the plunger 40. The lock plate 33 is held against the flange 42 by means of a narrow annular shoulder 43 integral with support 35. The flange 42 has a radial groove 45 which extends in a longitudinal direction (see FIG- URES 2 and 3) to permit radial motion of arms 22. The flange 42 has a groove 47 formed in its rear face to accommodate the sliding movement of primer carrying member 18.

A bore 49 extending longitudinally through the axial center of support 35, provides means to receive plunger 40 therein, the latter being suitably surrounded by a biasing spring 51. One end of the spring engages an annular shoulder 53 of the surrounding member 35, and the other end reacts against a flanged shoulder 52 of plunger 40 to bias the latter toward and against primer carrying member 18. To preclude the firing of plunger 40, the latter is releasably held in locking position by means of one or more balls 55 slidably positioned within an aperture 57 in support 35, and arranged in contact with a tapered portion 58 of plunger 40 and oppositely therefrom in contact with a raised shoulder 62 of the weight member 60 which forms part of impact sensitive means 54. The weight member 60 has an annular shoulder 65 on one end to receive annular portions 63 of the support 35. A central opening 59, of weight 60, into which portions of support 35 protrude, provides small depressions 61 therein to receive the balls 55, when responsive to impact upon the device the balls are jarred free of engagement with tapered portion 58. Hence, the weight 60 is loosely mounted to the support 35 and is held merely by the friction between the taper portion 58 of the plunger 40 and raised shoulder 62 of the weight 60. In unarmed position an edge 64 of the locking arms 22 is in radial engagement with weight 60 to prevent the latter from moving.

The arming delay mechanism 68 comprises a movable diaphragm disk 66 slidably mounted on shaft 67, one end of the shaft extending into and through bore of end cap 12. The diaphragm disk 66 is sealingly surrounded by a bellows 71 which has an enlarged end 72 fixedly disposed within and annularly around stationary cap 12, and other portions of bellows 71 circumferentially surround the diaphragm disk 66 whereby the bellows is mounted to permit longitudinal movement of the diaphragm between the bellows and casing 10. This arrangement provides a low friction seating base for the diaphragm and a sealed forward chamber 70, between the cap 12 and the movable diaphragm. The fit of shaft 67 with respect to aperture 15 permits water to enter therebetween into the forward chamber 70 allowing water pressure to act upon the diaphragm 66 when the missile is in motion. This presupposes, of course, that the exploder is mounted within a missile and, in accordance with the invention, is exposed to the medium in which the missile operates.

A- stationary sealed barrier 74 is spacedly mounted with respect to the movable diaphragm 66 and therebetween a biasing spring 76 is disposed opposing the longitudinal movement of the diaphragm. The barrier 74 provides circumferentially an annular groove 78 to receive an O-ring 79'.

A central aperture 75 in the barrier member 74 receives a cylindrical moving element 81 which at one end is rigidly connected to shaft 67 and at its opposite end is provided with an annular recess 82 to pivotably receive part of arms 22.

The two elongated locking arms 22 are mounted 180 apart. They may be formed by stamping, utilizing any suitable rigid material. At one end 25 the arms 22 are hook shaped and connected in groove 82 of the moving member 81 and a more intermediate portion provides a shoulder 64 for purposes hereinafter further explained. Part 23 of arms 22, near the tail end of the device provides for locking engagement with primer carrying member 18. The arms are pivotably mounted at 83 to the stationary barrier member 74. Hence, a longitudinal movement of the moving member 81 results in a radially outward movement of the latching ends 23 of arms 22. The outward movement of the arms is opposed by compression springs 85, which are longitudinally extensive with the arms, and surround rods 86. Each of the rods 86 is mounted at one end to the flange portion 42 of the support 35, and at its opposite end to a pivotable support 88 attached to arm 22. To provide rigidity in the construction, between the barrier member 74 and the support member 35, a plurality of rods 90 may be utilized to connect the two members as shown. In addition a clamp spring 100 disposed in annular groove 101 and engaging barrier member 74 precludes the latter to move freely.

A back chamber 92 is formed in the space between diaphragm 66 and barrier 74, and has one or more openings or conduits 93 providing access means to the ambient sea water. As a consequence, the chamber 92 fills rapidly with water upon launching of the missile. To prevent the water from filtering through aperture 75, a second bellows 95, similar to bellows 71, sealingly surrounds a flanged projection 94, of barrier 74, and moving element 81. The bellows 95 is retained in position by a washer 96 securing one end of the bellows against the moving element 81, and the outer lip of the bellows is secured against projection 94 by means of a flanged cylindrical cap 98 mounted thereagainst with a press fit.

As an additional safety measure a compression spring 105, one end thereof being surrounded by a shell 107, may be disposed in bore 190 of support 35, see FIGURES 2 and 3, and when the device is in unarmed condition the shell abuts against primer carrying member 18 at a point near 108. Thus, after member 18 completes its transverse movement in groove 47 the bore 109 registers with slot 24 and the shell 107 is biased into the slot. This prevents any further movement of the primary carrying member 10 after arming.

In operation, just prior to launching the device, a safety pin, not shown, which projects through bore 103 of shaft 67 and engages the cap 12, is removed, leaving the two springs as the sole means of maintaining unarmed condition. After launching the missile and upon reaching some degree of motion, impingement of water on the nose will produce a dynamic pressure at the forward end of shaft 67. Sea water motivated by this dynamic pressure will flow through the clearance 13 gradually filling the forward chamber 70 and thereupon moving diaphragm 66 slidingly on shaft 67 toward the barrier member 74.

In initial position the diaphragm 66 is adjacent to the cap member 12, and is maintained in that position by means of the spring 76 which holds the diaphragm in its full forward position at the time of assembly and prior to firing the device. The device may be structurally so arranged that only a slight pressure differential will exist between forward chamber 70 and back chamber 92. As the missile gains forward speed a differential pressure will be established along the length of annular clearance 13. Initially the pressure in the forward chamber 70 and the back chamber is approximately equal to that of the surrounding static sea. Since the clearance 13 permits only a gradual entrance of the water into the forward chamber, the forward chamber 70 is only slowly filled, the rapidity depending upon the forward speed of the missile. Upon filling the chamber 70 the pressure therein increases slightly, overcoming the bias of spring 76 and causing the diaphragm 66 to move toward the barrier 74. The water contained in chamber 92 is then gradually displaced through the apertures 93 into the sea.

No arming takes place in the exploder until the diaphragm 66 has travelled the distance to washer 96 and abuts thereagainst. An immediate build up of pressure in chamber 70 results. The pressure thus acting upon the large area of the bellows 71 and the diaphragm imposes a substantial load on the shoulder 96. This load causes the moving member 81 to move slightly longitudinally toward the tail end thereby transferring a force through the pivotable arrangement 83 onto the arms 22. The pressure is sufficient to overcome the restraining force of the springs 85 causing the arms 22 to move radially outward thereby removing their locking ends 23 from the slots 24 in the member 18, and thereby permitting springs 26 to slide the member 18 from the unarmed position shown in FIGURE 3 to the armed position shown in FIGURE 2. The toggle action of the springs 85 provides a diminishing torque resistance to the arms as they move so that a positive snap action is assured. The lifting of the arms permits the spring bias 26 of the primer carrying member to move the latter in line with the firing pin as aforestated. Thereafter the locking plate 33 is biased by the leaf spring 37 to prevent the return of the arms. The position of arms 22 in such retracted position has also the effect to remove the restraining shoulder 64 of arms 22 from the weight 60. In this condition the weight is now held in place solely by the wedging action of the balls '55. A slight impact upon the device will tear the weight from its position, releasing the balls and allowing the spring biased plunger to hit the primer charge, thereby initiating the explosion of the device.

I claim as my invention:

1. A hydrodynamically armed automatic underwater exploder comprising: an elongated casing having a central axis and a first and a second opening for admitting water, the axis of the first opening being substantially parallel and the axis of the second opening being substantially at right angle with respect to the central axis of said elongated casing; a partition member secured to and disposed within the casing dividing the casing into a forward and rearward chamber, said openings being located in said forward chamber; arming means operably disposed within said rearward chamber, portions of the arming means extending through said partition member; arming delay means including said openings operably associated with said forward chamber of said casing and responsive only to hydrodynamic pressure through said first opening, said delay means including diaphragm means movably disposed within said forward chamber between said first and second opening and axially displaceable therebetween and operatively connected with the said portions of said arming means to actuate the latter in response to hydrodynamic pressure acting against said diaphragm means; a spring member between the diaphragm means and the partition member and effective to retard the displacement of the diaphragm means; and sealing means effective to sealingly connect the said diaphragm means to the casing.

2. A hydrodynamically armed automatic underwater exploder comprising: an elongated casing having a central axis and a first and second opening for admitting water, the axis of the first opening being substantially parallel and the axis of the second opening being substantially at right angle with respect to the central axis of said elongated casing; a hollow body in the casing; a firing plunger slidably disposed in the body; safety means normally maintaining said firing plunger inetfective and movable to an operating position to render said plunger effective; a plurality of levers locking the safety means in its normal position against movement; a plurality of elongated spring members constituting an over-center toggle device, each spring member having one end pivotably mounted to one of said levers and the opposite end thereof secured to said body to effect a snap action in said levers in response to movement of said levers; diaphragm means movably disposed in said casing dividing said easing into a forward and a rearward chamber, said first opening being located in the forward chamber and! the second opening being located in the rearward chamber; arming delay means for said levers including said openings operably associated with said forward chamber of said casing and responsive only to hydrodynamic pressure through said first opening and effective to displace said diaphragm sealing means effective to sealingly connect the said diaphragm means to the casing; and a spring member abutting the diaphragm and retarding the axial displacement thereof.

3. A hydrodynamically armed automatic exploder according to claim 2, characterized in that said casing includes a front cap removably attached to the forward chamber of said casing and the cap being formed with the said first opening; and said sealing means being of annular form and providing at one axial end a headed portion sealingly surrounding portions of the circumference of said front cap and in sealing engagement with the forward chamber of said casing, and at the other axial end being secured to said diaphragm means, said sealing means also having folded portions circumferentially surrounding said annular diaphragm means and effective to provide a resilient low friction sliding support between said diaphragm and said casing.

References Cited UNITED STATES PATENTS 2,469,352 5/ 1949 Lauritsen 10281 2,807,210 9/1957 Wales 102--70 2,827,850 3/1958 Muzzey 102-78 X 2,859,696 11/1958 Burg 102-81 X 2,926,609 3/1960 Van Goey 10281 X VERLIN R. PENDEGRASS, Primary Examiner.

US. Cl. X.R. 102-7 

